I am a Junior Civil Engineering major at Loyola Marymount University and I am currently involved in working on a service project to rehabilitate a small lake in Encino, Ca. The lake is located on the site of the Holy Spirit Retreat Center. The idea for the project is to recycle greywater form the washing machines on site through a wetland filtration system to replenish the lake on site that has dried up recently in the drought. I would really appreciate some help on what kind of permits need to be obtained to make this happen? Or if it is even possible. Also if anyone has any insight about specific agencies or even people to contact that would be very helpful. We’re just trying to get started so ANY insight is helpful. Thank you!

Though it’s technically possible to treat greywater with a constructed wetland so it’s of suitable quality to fill a lake/pond you most likely won’t be able to obtain permits for it. You would need to prove the quality of treated greywater is suitable, which most likely would mean daily testing (like they do at wastewater treatment plants) and this would be cost prohibitive. If you have progressive public health, environmental health, and building departments where you’re working, perhaps you could use a NSF 350 certified treatment system and then be allowed to use the water for how you describe. Spray irrigation is technically allowed with NSF 350 certified systems, but I’m not certain about surfacing treated greywater so you’d need to look into it.

Alternatively you could look into stormwater capture for filling the lake- perhaps diverting rainwater from lots of building roofs and surface runoff.

To start, I’d try to find a progressive person in either of the department I mentioned above and ask them what they think about your idea, or ask California based engineering firms, like Sherwood Engineering, who do innovative water projects and see if they have any similar projects.